Method for controlling digital film play-count and a system thereof

ABSTRACT

The invention discloses a method for controlling digital film play-count and a system thereof, wherein a play-count parameter is added into a KDM file where a key delivery message used for controlling film play is embedded, detecting the play-count parameter for a playing film, setting RSA key abstracts of an FDM packager of all authorized contracting film producers, safely importing the KDM and play-count into a security module, detecting the play-count parameter for a playing film. The film is not permitted to play unless existing play-count is less than the authorized play-count in the FDM. The invention fulfills the requirements and demands for controlling the distribution and playback of digital films in the second-tier market using technologies such as the authorized play-count and a method to charge on the basis of play-count.

FIELD OF THE INVENTION

The present invention relates to the field of digital film playing, inparticular to a method for controlling digital film play-count and asystem thereof.

BACKGROUND

At present, in the existing digital film projector, a display screen istypically set up to display the relevant information from the projector,for example, the films to be played, the playing operations and relevantparameters in the film playing process etc. The display screen isusually connected by a control circuit to a storage unit in theprojector, and it is usually operated by an operator.

With the popularization of digital film entertainment, the second-tiermarket and its additional requirements for digital film playback haveemerged. For example, private cinema viewers are eager to adoptprofessional digital film players so as to enjoy first-run theatricalfilm releases at the comfort of their own homes; further, there are somepersonalized demands in the film market, such as ordering and watchingof a particular post theatrical film when desired. These services areusually provided in a movie premiere, a party, or as part of somecommercial activity. In addition, the demands for watching first-run andpost-theatrical film releases call for a system that is capable ofcharging on a play-count. However, existing digital film projectionsystems cannot meet the requirements and demands of this second-tiermarket due to their inherent limitations of obtaining authorization fromdigital film playback.

Some of the reasons are as follows.

For copyright protection, existing cinema projection systems usuallyadopt a KDM (Key Delivery Message) licensing method, which means that acinema needs to apply for a KDM from a film distributor. The KDM is afile for delivering a key; it mainly contains the following three kindsof information: a content decryption key, a key parameter and a TDL(Trusted Device List). The key parameter is mainly the key's time window(valid time period), i.e., the scheduled time for playing a film. TheTDL is an information list of the valid and authorized equipment to playthe film.

The encrypted film content and its key are generated after a digitalfilm is compressed, encrypted and packaged. The encrypted film contentand its relevant information form a Digital Cinema Package (DCP), andare transmitted to an exhibitor or a cinema; the key, upon being furtherencrypted, will be digitally signed along with other relevantinformation to form a KDM, and is then transmitted to authorized cinemasby a film distributor or its entrusted film producer. Upon receiving theKDM, the cinema can decrypt and play the encrypted digital film only bycorrectly extracting the film content and obtaining the key afterdecryption. In addition to the key, the KDM also includes the valid timeperiod and a TDL for the key etc. Therefore, by virtue of suchinformation, the film distributor can control both the film playingschedule and the projector. In other words, a film cannot be played ifthe time period carried by the KDM is exceeded, or if it is in aprojector not in connection with the server designated by the KDM.

The key's time window is determined upon communications among the filmdistributor, the cinema and the film producer. After the key hasexpired, the cinema can apply for an extension if necessary. After theapplication for extension is approved, the key must be reproduced, andthe film distributor (e.g. The China Film Group in mainland China)issues a “Notice of Extension” on its official website and indicates theexpiration date of the extended key.

The aforementioned KDM distribution method is defined as part of theDigital Cinema Initiative (DCI) standard, and the KDM format cannot bealtered arbitrarily. At present, digital film projection technology canbe broadly categorized on the basis of resolution ratio, namely into 4K,2K, 1.3K and 0.8K. 4K (resolution ratio of 4096×2016 8.25 megapixel)projection is currently the state-of-the-art for commercial digitalprojection, and it is not commonly adopted even in major cinema networksin first-tier cities. 2K (resolution ratio of 2048×1080 2.21 megapixel)is currently the international standard for film projection. 2K iseffectively the same as 4K in terms of synchronized film playing, as thedifference of the visual effects between 2K and 4K can only be seen on adisplay screen of more than 20 m in width. 1.3K (a resolution ratio of1280×1024 1.31 megapixel) is the current Chinese National standard,whereas 0.8K (resolution ratio of 1024×768 0.786 megapixel) is a filmprojection standard used mainly in rural China. Overall, there is a wideadoption of various projection standards across China.

Due to copyright restrictions, digital films, when exhibited in cinemas,have to be played on specialized hardware, such as a dedicated chip inthe server of a digital film projector, using a specialized process suchas the abovementioned KDM method for playing digital films to manage theplayable time, the authorized server information, and the key used fordecrypting a film for playing. However, at present, the KDM can onlycontrol the playable time period, which is appropriate for commercialcinemas due to their fixed daily schedule for playback of digital films.However, this is unsuitable for the purposes of secondary markets suchas private cinemas. In addition, post-theatrical release films (inabovementioned DCP formats) cannot be played on-demand. Unlike a film inits theatrical release, the requirements for playing a film aftertheatrical release are not as high. Accordingly, subsequent distributionis difficult, and on-demand requirements are not met. Based on the priorart, digital films cannot be played under the control of play-count inthe second-tier market in private cinemas during and after theatricalrelease.

Therefore, the prior art needs to be improved and developed.

BRIEF SUMMARY OF THE DISCLOSURE

In consideration of disadvantages of the prior art, embodiments of thepresent invention aims to provide a method for controlling digital filmplay-count and a system thereof, and providing a method and system forlicensing to play digital films that is capable of charging paymentsbased on play-count. The technical solutions of the present inventionare shown as below:

A method for controlling digital film play-count, wherein it comprisesthe following steps:

A, in a process of generating a license file for playing a digital film,a play count parameter is added into a KDM file where a key deliverymessage used for controlling film play is embedded, for generating afilm delivery message file also known as the FDM file;

B, setting key abstracts of the RSA public key in a FDM packager of allauthorized contracting film producers in a player, adding a key abstractof the FDM packager of an authorized contracting film producer into theFDM file and importing it into a security module of the player;

C, detecting the play count parameter of a playing film, detecting andjudging a valid play count on the basis of different film footages orframe length percentage so as to confirm a valid play of the currentfilm, and using a TLS (Transport Layer Security Protocol) encryptionmessage for informing the security module of the valid play of the film;and

D, judging whether the current play count is greater than the play countparameter in the KDM file; the film is permitted to play if not, andprohibited if so.

The method for controlling digital film play count, wherein the step Aspecifically includes:

In the process of generating a license file for playing a film, a TAGfor extending an original KDM is used for packaging an original KDM filewhere a key delivery message used for controlling film play is embeddedtogether with a parameter of an authorized play count, to generate afilm delivery message file known as an FDM file.

The method for controlling digital film play-count, wherein the step Bspecifically includes:

B1, key abstracts of the RSA public key in a FDM packager of allauthorized contracting film producers are pre-stored in a player, andstored in a key abstract list;

B2, adding a key abstract of the FDM packager of an authorizedcontracting film producer into the FDM file, and verifying whether thekey abstract in the FDM file is identical to one of the pre-stored keyabstracts, if yes, the KDM file and play-count parameter are permittedto be respectively extracted from the FDM file, and imported into theplayer; and

B3, the play-count parameter is stored in a security module of theplayer and encrypted by an AES key.

The method for controlling digital film play-count, wherein step Cspecifically includes:

C1, detecting the play-count parameter for a playing film; and

C2, detecting and judging a valid play-count on the basis of differentfilm footages or frame length percentage: it is deemed a valid play ifit has played for more than 30 minutes or if has played more than 30% ofthe total frame even though the played duration is less than 30 minutes;and using the TLS (Transport Layer Security Protocol) to inform thesecurity module for adding 1 to the current play-count in a counter.

The method for controlling digital film play-count, wherein step D alsoincludes:

Upon confirmation of the play-count, a user's operating instructions arepermitted to be received throughout the duration of the film play, forexample, interrupting and then resuming play or resuming to the samefilm multiple times.

The method for controlling digital film play-count, wherein step a alsoincludes: the play-count parameter and the KDM file are bundled togetherand packaged as the FDM file, serving as an extension in conformancewith the DCI KDM Standard, wherein the KDM file is the same as anoriginal DCI KDM file.

A system for controlling digital film play-count, wherein it comprises:

A play-count generating module, used for adding a play-count parameterinto a KDM file where a key delivery message used for controlling filmplay is embedded in a process of generating a license file for playing afilm, and for generating a film delivery message file known as an FDMfile;

An import control module, used for setting key abstracts of the RSApublic key in a FDM packager of all authorized contracting filmproducers in a player, adding a key abstract of the FDM packager of anauthorized contracting film producer into the FDM file and importing itinto a security module of the player;

A play detection module, used for detecting the play-count parameter ofa playing film, detecting and judging a valid play-count on the basis ofdifferent film footages or frame length percentage so as to confirm avalid play of the current film, and using a TLS (Transport LayerSecurity Protocol) encryption message for informing the security moduleof the valid play of the film;

A play control module, used for judging whether the current play-countis greater than the play-count parameter in the KDM file, the film ispermitted to play if no, and prohibited if yes.

The system for controlling digital film play-count, wherein the importcontrol module comprises:

A storage unit, used for pre-storing key abstracts of the RSA public keyin an FDM packager of all authorized contracting film producers in aplayer, and storing the key abstracts in a key abstract list;

An addition unit, used for adding a key abstract of the FDM packager ofan authorized contracting film producer into the FDM file, and verifyingwhether the key abstract in the FDM file is identical to one of thepre-stored key abstracts: if so, the KDM file and the play-countparameter are permitted to be respectively extracted from the FDM file,and imported into the player;

An encrypted storage unit, used for storing the play-count parameter ina security module of the player and the play-count parameter isencrypted by an AES key.

The play detection module comprising:

A detecting unit, used for detecting the play-count parameter for aplaying film;

A counting control unit, used for detecting and judging a valid playcount on the basis of different film footages or frame lengthpercentage: it is deemed a valid play if it has played for more than 30minutes or if has played more than 30% of the total frame even thoughthe played duration is less than 30 minutes; and using the TLS(Transport Layer Security Protocol) to inform the security module foradding 1 to the current play-count in a counter.

The system for controlling digital film play-count, wherein theplay-count parameter and the KDM file are bundled together and packagedas the FDM file, serving as an extension in conformance with the DCI KDMStandard, wherein the KDM file is the same as an original DCI KDM file.

The present invention provides a method for controlling digital filmplay-count and a system thereof, wherein a play-count parameter is addedinto a KDM file where a key delivery message used for controlling filmplay is embedded, detecting the play-count parameter for a playing film;the film is permitted to play if the current play-count is less than theplay-count parameter in the KDM file, and the film is prohibited to playif the current play-count is greater than the play-count parameter inthe KDM file. By using the player provided in the present inventionwhich is capable of charging on play-count, digital films to be playedin second-tier markets can be controlled. The distribution of digitalfilms during and after theatrical releases can be precisely controlledto meet the demands of the second tier digital film market, namely usingthe authorized play-count and allowing charging based on the actualplay-count.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow chart of a preferred embodiment of a method forcontrolling digital film play-count provided by an embodiment of thepresent invention.

FIG. 2 is a structural diagram for a tamper-prevention method during theprocess of generating a play-count and a mode of transmission accordingto an embodiment of the present invention.

FIG. 3 is a schematic diagram of a process for preventing an import of atampered play-count according to an embodiment of the present invention.

FIG. 4 is a flow chart to illustrate the detection and changing of theplay-count on the basis of valid play-count according to an embodimentof the present invention.

FIG. 5 is a flow chart of a method for calculating a specific play-countaccording to an embodiment of the present invention.

FIG. 6 is a functional block diagram of a system for controlling digitalfilm play-count according to and embodiment of the present invention.

FIG. 7 illustrates exemplary common components of a system such as theone of FIG. 6, according to an embodiment of the present invention.

DETAILED DESCRIPTION

The present invention provides methods for controlling digital filmplay-count and a system thereof. To improve the clarity andunderstanding of the objective of this invention, further detaileddescriptions of the present invention is made by using the drawings andexamples. Embodiments described here are used for explanation of thepresent invention, but not limited to them.

The present invention can provide a method for controlling digital filmplay-count, wherein it can include the following steps:

Step S100, in a process of generating a license file for playing a film,a play-count parameter can be added into a KDM file where a key deliverymessage used for controlling film play can be embedded, for generating afilm delivery message file known as an FDM file;

In this embodiment, the license file for controlling the film playingcan be produced in advance; in the process of generating the licensefile, a play-count parameter can be authorized; the play-count parametercan be added into the KDM file where the key delivery message used forcontrolling film play can be embedded, for generating the film deliverymessage file known as the FDM file. The KDM file, as an original DCI KDMfile, can be kept intact without any alterations, thus maintaining itscompatibility with the DCI standard. In this embodiment, the play-countparameter and the KDM file can be bundled together for transmitting andpackaged as an FDM file, thereby serving as an extension in conformanceto the DCI KDM Standard; its extension TAG can be<NonCriticalExtension>.

In the present invention, in order to explicitly extend the KDM TAG andpackage the play-count content, a FDM (Film Delivery Message) fileformat can be put forward, for extending and generating the followingfile on the basis of the KDM; the newly added TAG can be saved under,for example, NonCriticalExtensions, with the embedded KDM completelypackaged in its original form.

In the Step S100, in the process of packaging and generating the FDMfile, an extended special KDM file (namely FDM format) for packaging KDMand play-count can be used; wherein, the Step S100 can specificallyinclude:

In the process of generating a license file for playing a film, a TAGfor extending an original KDM can be used for packaging an original KDMfile where a key delivery message used for controlling film play can beembedded together with a parameter of an authorized play-count, togenerate a film delivery message file called an FDM file.

In this embodiment, Step S100 can provide a method of the generation andthe transmission of the play-count—the KDM and the play-count can bepackaged together by the FDM file. In order to maintain the securityclassification of the existing DCI KDM (DCI: DigitalCopyrightldentifier;KDM: Key Delivery Message) unchanged, an RSA digital signature methodwhich can be the same as the KDM can be used in the present invention,which makes the KDM of imported films compatible with the KDM ofdomestic films and reuses all of the existing film distribution process,using the TAG and embedding with the original KDM and desirableplay-count into an outer layer KDM (namely, the FDM file). The FDM file,as an extension of the original KDM, can be a security certificate inconformance with the DCI KDM. In essence, the FDM can be packaged andtransmitted together with the play-count under the circumstance ofmaintaining all characteristics of the original KDM unchanged. The RSAdigital signature can be used to guarantee the security of the FDM fileduring transmission.

As shown in FIG. 2, in this embodiment, a KDM file (namely, the originalKDM file) can be generated by an original KDM generator by combining atime window, an equipment number and a decryption key; then, theoriginal KDM file and the play-count parameter can be bundled togetherby the FDM generator (a KDM wrapper), and embedded into a special KDMTAG, thus generating an FDM file.

The FDM file can be a kind of KDM file using the extended TAG, where thedigital signature algorithm and the client machine serial number can beidentical to the generated KDM file. It can be compatible with DCI KDMStandard, maintaining the embedded FDM file to be identical to the KDMfile in terms of security level, effectively preventing the FDM filefrom being tampered with during transmission. It can also minimize therisk and expenditure when compared with another method of distributingthe KDM and FDM files separately. The RSA algorithm (an encryptionalgorithm frequently-used for encryption of digital film, not furtherdescribed here) adopted for digital signature can be consistent with theKDM.

By using the embodiment provided in the present invention which can becapable of charging on play-count, digital films to be played insecond-tier markets can be controlled. The distribution of digital filmsduring and after theatrical releases can be precisely controlled to meetthe demands of the second tier digital film market, namely using theauthorized play-count and allowing charging based on the actualplay-count.

Step S200, setting key abstracts of the RSA public key in a FDM packagerof all authorized contracting film producers in a player, adding a keyabstract of the FDM packager of an authorized contracting film producerinto the FDM file and importing it into a security module of the player;

In this step, in order to prevent the FDM file imported into the playerfrom being tampered with, a key abstract list of RSA public key in theFDM packager of all authorized contracting film producers can bepre-stored in the player. This way, only ones matching one of thepre-stored FDMs generated by those authorized contracting film producerscan be imported into the player. Step S200 can specifically include:

B1, key abstracts of the RSA public key in a FDM packager of allauthorized contracting film producers can be pre-stored in a player, andstored in a key abstract list;

B2, adding a key abstract of the FDM packager of an authorizedcontracting film producer into the FDM file, and verifying whether thekey abstract in the FDM file is identical to one of the pre-stored keyabstracts, if so, the KDM file and play-count parameter can be permittedto be respectively extracted from the FDM file, and imported into theplayer; and

B3, the play-count parameter can be stored in a security module of theplayer and encrypted by an AES key.

Specifically, as is shown in FIG. 3, there are 4 key points in importingthe FDM file into the player:

1, the import procedure can be divided into 2 steps, both of which canbe conducted in the security module (SM), Both the KDM file and theplay-count parameter can be separated and then processed respectively.The KDM file can be checked strictly in accordance with the DCIprotocol. The play-count can be stored in the security module andencrypted by an AES key. The AES key can be stored in a security chip(for example, DALLAS DS3641 or DS5250 security chip etc.) certified bythe DCI. In other words, the file containing the play-count can bestored in the security chip and encrypted by the AES key, and the SHA1abstract of the storage file can be stored in the security chipcertified by the DCI. The security chip can include, but is not limitedto, DS3641 or DS5250 etc. In case the file where the play-count storedis tampered with, the security module can perform a detection bycomparing SHA1 values previously stored in the security chip, and callfor the relevant processing module to take protective measures;

2, the above-mentioned processes can be conducted within the scope ofthe security module.

3, A film player software that contains the RSA key abstracts of a FDMpackager of all authorized contracting film producers, mainly for thepurpose of preventing malicious tampering of the FDM. Authority to acontracting film producer can be given by adding and importing anauthorized license agreement of the FDM packager, or by storing theauthorized key abstract into an executable file, which can only berealized by an updated software;

4, the key abstracts of the FDM packager can be a SHA1 algorithm inconformance with the FIPS Standard.

In a process of importing the FDM into a player, embodiments of thepresent invention can adopt the key abstracts of the FDM packager of allauthorized contracting film producer for preventing import of atampered-with play-count, and the key abstracts can be encrypted by theAES key and then stored in the security module. In other words, the RSAkey abstracts of the FDM packager of all authorized contracting filmproducers can be pre-stored in the player for preventing import ofunauthorized or tampered-with play-count.

Step S300, detecting the play-count parameter for a playing film,detecting and judging a valid play-count on the basis of different filmfootages or frame length percentage so as to confirm a valid play of thecurrent film, and using a TLS (Transport Layer Security Protocol)encryption message for informing the security module of the valid playof the film;

In this embodiment, to use the play-count parameter securely, theprocess can apply the logic for valid play verification and play-countaccumulation within the security module, meanwhile, the play controlmodule can adopt an algorithm to ensure that the player can query theplay-count condition before playing a film, and judge reasonably whethera valid play takes effect on the basis of different film footages at thebeginning to play the film, and further update the actual play-count,thus ensuring both the accuracy and validity of the play-count.

Specifically, the method used in the play-count can be as below:

C1, detecting the play-count parameter for a playing film; and

C2, detecting and judging a valid play-count on the basis of differentfilm footages or frame length percentage: it can be deemed as a validplay if, for example, it has played for more than 30 minutes or if ithas played more than 30% of the total frame even though its duration ofplay is less than 30 minutes; and using the TLS (Transport LayerSecurity Protocol) to inform the security module for adding 1 to thecurrent play-count in a counter.

As shown in FIG. 4, when a digital film player is used for playing afilm, both the querying of valid play condition and the aggregation ofplay-count updates can be conducted in the security module (SM).Building on the original KDM verification process, the security checkalgorithm can be newly added with the function of checking theauthorized play-count and the actual play-count. There are 3 keypoints: 1. Both the authorized play-count and the actual play-count canbe stored in the security module, and the check algorithm can beconducted in the security module; 2. The TLS can be used by the playerfor carrying out communications with the security module, so as toprevent hackers from hacking; 3. A SHA1 abstract of the storage file inthe security module can be stored in the security chip, so as to preventhackers from tampering.

In other words, in this embodiment of the present invention, a validplay can be checked on the basis of different film footages or framelength percentage, TLS encryption message can be used for informing thesecurity module of a valid play, and logical judgment of play-count canbe conducted in the security module.

Step S400, judging whether the current play-count is greater than theplay-count parameter in the KDM file, the film can be permitted to playif not, and prohibited if so.

Specifically, upon confirmation of the play count, a user's operatinginstructions can be permitted to be received throughout the duration offilm play, for example, interrupting and then continuing playing orresuming to the same film multiple times.

As shown in FIG. 4, concrete steps for detecting the play-count caninclude:

Step 1, play-count query: the play module can query the play countstored in the security module;

Step 2, the security module can judge whether the authorized play-countis greater than the current play-count, the film can be prohibited toplay if not, and permitted if so; and

Step 3, when the film is permitted to play, the current play-count canbe incremented by 1. It can be deemed a valid play if it has played formore than 30 minutes or if it has played more than 30% of the totalframe even though its film play duration is less than 30 minutes.

In this embodiment of the present invention, there can be 5 key pointsfor the controlling the play algorithm: 1, the conditions for judgingwhether it constitutes a valid play are self-adaptive; in other words,on the basis of, for example, 30% of the film footage (frame), the TLS(Transport Layer Security Protocol) encryption message can be used forinforming the security module to change the current play-count; 2, incase of confirming failure of film play, the play module can repeat therequest until it succeeds; 3, once it is confirmed as a successful orvalid play, the play module can keep a record to avoid double counting;4, the operation for judging a valid play can be carried out in aseparate thread; 5, users can pause or continue playing the same filmmultiple times.

In this embodiment of the present invention, after a valid play isconfirmed, users can pause or continue playing the same film many times.The method will preclude double counting, and users can continue playingthe same film multiple times.

From the above, it can be seen that, in the embodiment of the presentinvention, both algorithm and data for detecting the play-count can bestored in the security module, and the communication between thesecurity module and the play module can be realized using the TLSsecurity protocol. The algorithm for judging a valid play can be basedon films of different footages. As for a longer film (for example, morethan 90 minutes), it can be deemed a valid play if it has played formore than 30 minutes; as for a shorter film, a valid play can be judgedon the basis of a reasonable percentage (for example 30%) of the lengthof the film (including time and frame). It should be pointed out that,either alteration of self-adapting parameters or different applicationsof frame percentage are deemed as within the scope of the claims. Thealgorithm design can be effectively adaptable to control the play-countof films of different footages.

After a valid play is finished, in the process of subsequent play, userscan pause or continue to play the same film for many times. This isbecause users in private cinemas and the second-tier market require moreflexibility in their consumption of digital films. For example, theymight pause the playing of a film for receiving a visitor, and perhapscontinue to watch the film later on. The claims can contain twotechnologies as below: 1, the command of “continue or resume playing”can be added in addition to general play control commands, so as to takethe previous pause position as a mobile parameter; 2, To continueplaying, an algorithm for allowing the security module to skip theplay-count check can be added so as to ensure users can watch the entirefilm.

The play-count can be taken as the basis for payment charges to users.The real-time play-count can be stored in a local database and comparedwith the play-count in a security log, so as to realize accuratecharging. The play-count, as an extension of the security log, can bewritten down as an existing security log item. Regarding the play log ofplay-count, the local database can verify its consistency with thesecurity log, serving as the basis for payment charges to users.

Based on the above-mentioned embodiments, the present invention can alsoprovide a system for controlling digital film play-count, as shown inFIG. 6, the system can include:

A play-count generating module 610, used for adding a play-countparameter into a KDM file where a key delivery message used forcontrolling film play can be embedded in a process of generating alicense file for playing a film, and for generating a film deliverymessage file called as a FDM file, specifically as described in theabove-mentioned Step S100;

An import control module 620, used for setting key abstracts of the RSApublic key in a FDM packager of all authorized contracting filmproducers in a player, adding a key abstract of the FDM packager of anauthorized contracting film producer into the FDM file and importing itinto a security module of the player, specifically as described in theabove-mentioned Step S200;

A play detection module 630, used for detecting the play-count parameterfor a playing film, detecting and judging a valid play-count on thebasis of different film footages or frame length percentage so as toconfirm a valid play of the current film, and using a TLS (TransportLayer Security Protocol) encryption message for informing the securitymodule of the valid play of the film, specifically as described in theabove-mentioned Step S300;

A play control module 640, used for judging whether the currentplay-count is greater than the play-count parameter in the KDM file, thefilm can be permitted to play if not, and prohibited if so, specificallyas described in the above-mentioned Step S400.

The import control module can include:

A storage unit, used for pre-storing key abstracts of the RSA public keyin a FDM packager of all authorized contracting film producers in aplayer, and storing the key abstracts in a key abstract list;

An addition unit, used for adding a key abstract of the FDM packager ofan authorized contracting film producer into the FDM file, and verifyingwhether the key abstract in the FDM file is identical to one of thepre-stored key abstracts: if so, the KDM file and the play-countparameter can be permitted to be respectively extracted from the FDMfile, and imported into the player;

An encrypted storage unit, used for storing the play-count parameter ina security module of the player and the play-count parameter can beencrypted by an AES key.

The play detection module can include:

A detecting unit, used for detecting the play-count parameter for aplaying film;

A counting control unit, used for detecting and judging a validplay-count on the basis of different film footages or frame lengthpercentage: it can be deemed a valid play if it has played for more than30 minutes or if it has played more than 30% of the total frame eventhough it has played for less than 30 minutes; and using the TLS(Transport Layer Security Protocol) to inform the security module foradding 1 to the current play-count in a counter.

The system for controlling digital film play-count, wherein, theplay-count parameter and the KDM file can be bundled together andpackaged as the FDM file, serving as an extension in conformance withthe DCI KDM Standard, wherein the embedded KDM file can be identical tothe original DCI KDM file.

The present invention can provide a method for controlling digital filmplay-count and a system thereof, wherein a play-count parameter can beadded into a KDM file where a key delivery message used for controllingfilm play can be embedded, detecting the play-count parameter for aplaying film; the film can be permitted to play if the currentplay-count is less than the play-count parameter in the KDM file, andthe film can be prohibited to play if the current play-count is greaterthan the play-count parameter in the KDM file, by using the playerprovided in the present invention which is capable of charging onplay-count, digital films to be played in second-tier markets can becontrolled. The distribution of digital films during and aftertheatrical releases can be precisely controlled to meet the demands ofthe second tier digital film market, namely using the authorizedplay-count and allowing charging based on the actual play-count.

In some embodiments, one or more of the modules discussed above can bestored and/or transported within any non-transitory computer-readablestorage medium for use by or in connection with an instruction executionsystem, apparatus, or device, such as a computer-based system,processor-containing system, or other system that can fetch theinstructions from the instruction execution system, apparatus, or deviceand execute the instructions. In the context of this file, a“non-transitory computer-readable storage medium” can be any medium thatcan contain or store the program for use by or in connection with theinstruction execution system, apparatus, or device. The non-transitorycomputer readable storage medium can include, but is not limited to, anelectronic, magnetic, optical, electromagnetic, infrared, orsemiconductor system, apparatus or device, a portable computer diskette(magnetic), a random access memory (RAM) (magnetic), a read-only memory(ROM) (magnetic), an erasable programmable read-only memory (EPROM)(magnetic), a portable optical disc such a CD, CD-R, CD-RW, DVD, DVD-R,or DVD-RW, or flash memory such as compact flash cards, secured digitalcards, USB memory devices, memory sticks, and the like.

The non-transitory computer readable storage medium can be part of acomputing system such as those discussed in the above-describedembodiments of the invention. FIG. 7 illustrates exemplary commoncomponents of one such computing system. As illustrated, the system 700can include a central processing unit (CPU) 702, I/O components 704including, but not limited to one or more of display, keypad, touchscreen, speaker, and microphone, storage medium 706 such as the oneslisted in the last paragraph, and network interface 708, all of whichcan be connected to each other via a system bus 710. The storage medium706 can include the modules of the embodiments discussed above. One ormore of these components can be optional and the system 700 can includeother components not illustrated in FIG. 7.

It should be understood that, the application of the present inventionis not limited to the above-mentioned embodiments. It will be possiblefor a person skilled in the art to make modifications or replacementsaccording to the above description, all of those modifications orreplacements shall all fall within the scope of the appended claims ofthe present invention.

What is claimed is:
 1. A method for controlling digital film play-count,the method comprising the steps of: A, in a process of generating alicense file for playing a film, adding a play-count parameter into aKey Delivery Message (KDM) file where a key delivery message used forcontrolling film play is embedded, for generating a film deliverymessage file also known as a Film Delivery Message (FDM) file; B,setting a fingerprint of an RSA public key in a FDM packager of allauthorized contracting film producers in a player, adding a key abstractof the FDM packager of an authorized contracting film producer into theFDM file and importing it into a security module of the player; C,detecting the play-count parameter of a playing film, detecting andjudging a valid play-count on the basis of different film footages orframe length percentage so as to confirm a valid play of the currentfilm, and using a Transport Layer Security Protocol (TLS) encryptionmessage for informing the security module of the valid play of the film;and D, judging whether the current play-count is less than theplay-count parameter in the KDM file, the film is permitted to play ifyes, and prohibited if not.
 2. The method for controlling digital filmplay-count according to claim 1, wherein Step A includes: in a processof generating a license file for playing a film, using a TAG forextending an original KDM for packaging an original KDM file where a keydelivery message used for controlling film play is embedded togetherwith a parameter of an authorized play-count, to generate a filmdelivery message file called an FDM file.
 3. The method for controllingdigital film play count according to claim 1, wherein Step B includes:B1, pre-storing, in a player, fingerprint of RSA public key in a FDMpackager of all authorized contracting film producers, and thefingerprint stored in a key abstract list; B2, adding a key abstract ofthe FDM packager of an authorized contracting film producer into the FDMfile, and verifying whether the key abstract in the FDM file isidentical to one of the pre-stored key abstracts, if yes, the KDM fileand play-count parameter are permitted to be respectively extracted fromthe FDM file, and imported into the playback system; and B3, storing theplay-count parameter in a security management module of the playbacksystem and encrypting the play-count parameter by an AES key.
 4. Themethod for controlling digital film play-count according to claim 1,wherein Step C includes: C1, detecting the play-count parameter for aplaying film; and C2, detecting and judging a valid play-count on thebasis of different film footages or frame length percentage: it isdeemed a valid play if it plays more than 30 minutes of long film whoselength is more than 90 minutes or else if it is more than 30% of thetotal frame although it plays less than 30 minutes; and using the TLS(Transport Layer Security Protocol) to inform the security module foradding 1 to the current play-count in a counter.
 5. The method forcontrolling digital film play-count according to claim 1, wherein Step Dfurther includes: upon confirmation of a valid playback, permitting auser's operating instructions to be received throughout the duration offilm play, for example, interrupting and then continuing playing orresuming to the same film multiple times.
 6. The method for controllingdigital film play-count according to claim 1, wherein Step A furtherincludes: bundling the play-count parameter and the KDM file togetherand packaging the play-count parameter and the KDM file as the FDM file,serving as an extension in conformance with the DCI KDM Standard,wherein the KDM file is an original DCI KDM file.
 7. A system forcontrolling digital film play-count, comprising: a play-count generatingmodule, used for adding a play-count parameter into a KDM file where akey delivery message used for controlling film play is embedded in aprocess of generating a license file for playing a film, and forgenerating a film delivery message file called an FDM file; an importcontrol module, used for setting fingerprint of the RSA public key in aFDM packager of all authorized contracting film producers in a player,adding a key abstract of the FDM packager of an authorized contractingfilm producer into the FDM file and importing it into a security moduleof the player; a play detection module, used for detecting theplay-count parameter for a playing film, detecting and judging a validplay-count on the basis of different film footages or frame lengthpercentage so as to confirm a valid play of the current film, and usinga TLS (Transport Layer Security Protocol) encryption message forinforming the security module of the valid play of the film; a playcontrol module, used for judging whether the current play-count isgreater than the play-count parameter in the KDM file, the film ispermitted to play if not, and prohibited if so.
 8. The system forcontrolling digital film play-count according to claim 7, wherein theimport control module comprises: a storage unit, used for pre-storingkey abstracts of the RSA public key in a FDM packager of all authorizedcontracting film producers in a player, and storing the key abstracts ina key abstract list; an addition unit, used for adding a key abstract ofthe FDM packager of an authorized contracting film producer into the FDMfile, and verifying whether the key abstract in the FDM file isidentical to one of the pre-stored key abstracts: if so, the KDM fileand the play-count parameter are permitted to be respectively extractedfrom the FDM file, and imported into the player; an encrypted storageunit, used for storing the play-count parameter in a security module andthe play-count parameter is encrypted by an AES key.
 9. The system forcontrolling digital film play-count according to claim 7, wherein theplay detection module comprises: a detecting unit, used for detectingthe play-count parameter for a playing film; a counting control unit,used for detecting and judging a valid play-count on the basis ofdifferent film footages or frame length percentage: it is deemed a validplay if it has played for more than 30 minutes of long film whose lengthis more than 90 minutes or else if it has played more than 30% of thetotal frame even though it has played for less than 30 minutes; andusing the TLS (Transport Layer Security Protocol) to inform the securitymodule for adding 1 to the current play-count in a counter.
 10. Thesystem for controlling digital film play-count according to claim 8,wherein the play-count parameter and the KDM file are bundled togetherand packaged as the FDM file, serving as an extension in conformancewith the DCI KDM Standard, wherein the embedded KDM file is identical tothe original DCI KDM file.